This invention relates to a hermetic reciprocating piston compressor, and in particular to a compressor having a single piece gasket valve plate assembly associated therewith.
Reciprocating compressors generally use a unitary valve plate to cover all the cylinders of the compressor. The valve plate includes a suction port and discharge port, which are respectively in fluid communication with a suction pressure chamber and a discharge pressure chamber of a cylinder head. Such valve plates are generally sealed to the cylinder head of a compressor by means of several gaskets. For example, in a dual piston assembly, three gaskets are used: one outer gasket to seal the periphery of the valve plate to the cylinder head, and two inner ring gaskets to seal each cylinder suction valve area to its corresponding suction chamber.
Valve plates and cylinder head assemblies have become relatively complex for certain compressors and can be quite costly to assemble and manufacture. Therefore, it is important to reduce the number of steps needed to assemble these compressors.
The use of multiple valve plate gaskets in compressors has been effective to seal and separate assembly parts. Notwithstanding this success, efforts are continuously directed toward increasing the rate of compressor assembly production. Considerations of manufacturability and costs impact on the desirability of the aforementioned prior art gaskets. For example, during initial manufacturing of the compressor assembly, the outer gasket must be installed independently of the inner ring gaskets. In addition, the inner ring gaskets may get out of proper alignment with the valve plate during assembly, especially during very high rates of automated production. Furthermore, the ring gaskets may adhere together during production resulting in two ring gaskets in the place where only one should be. Consequently, the next valve plate on the assembly line may have no gasket installed therein.
Thus, not only does the present use of multi-piece gaskets result in a greater time of manufacture and assembly, but may also result in the assembly of compressors with an improper number or placement of the separate gaskets.